<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>video()</title>
  </head>

  <body>
    <div style="text-align:center"> 
      <button onclick="playPause()">播放/暂停</button> 
      <button onclick="makeBig()">放大</button>
      <button onclick="makeSmall()">缩小</button>
      <button onclick="makeNormal()">普通</button>
      <br> 
      <br> 
      <video id="video1" width="420">
        <source src="winter-forest-hike.mp4" type="video/mp4">
        您的浏览器不支持 HTML5 video 标签。
      </video>
    </div>

    <script>
      var myVideo=document.getElementById("video1"); 

      function playPause() { 
        if (myVideo.paused) 
          myVideo.play(); 
        else 
          myVideo.pause(); 
      }

      function makeBig() { 
        myVideo.width=560; 
      }

      function makeSmall() { 
        myVideo.width=320; 
      }

      function makeNormal() { 
        myVideo.width=420; 
      }
    </script>

  </body> 
</html>
